The increasing number of frequency bands and standards in mobile communication systems increases the design complexity of mobile phones, as some mobile phones are now configured to operate using multiple standards across multiple frequency bands. In addition, the mobile phone may also include a Global Positioning System (GPS) receiver. In many mobile phones, these multiple frequency bands and standards are implemented by using multiple radio frequency (RF) transmitters and receivers within multiple signal paths that may be coupled to a single antenna using an antenna switch. The introduction of more and more frequency bands within the mobile phone, however, may cause some issues with respect to jamming due to the creation of distortion products within circuitry of the mobile phone and within the antenna switch itself.
In some cases, these antenna switches may be implemented using one or MOS switching transistors disposed on an integrated circuit substrate. In order to minimize distortion products, the substrates of the MOS switching transistors may be biased to a negative voltage and/or the gate driving voltage may be driven above a locally available supply voltage using one or more voltage boosting circuits, such as a charge pump circuit. According to common practice, antenna switches are tested to ensure functionality and performance. One way to test an RF switch is to verify its gross functionality at DC. Such a test, however, may not detect defects in the switching transistor or the voltage boosting circuits that may degrade RF performance of the RF switch under normal operating conditions.